2023 Fiscal Year Final Research Report

Improving the durability of concrete by using large quantity of by-product powders without hydraulic properties

Research Project

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Project/Area Number	21H01480
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 23010:Building structures and materials-related
Research Institution	Kyushu University
Principal Investigator	KOYAMA TOMOYUKI 九州大学, 人間環境学研究院, 准教授 (50215430)
Co-Investigator(Kenkyū-buntansha)	湯淺昇日本大学, 生産工学部, 教授 (00230607) 山本大介大分工業高等専門学校, 都市・環境工学科, 准教授 (40398095) 伊藤是清東海大学, 文理融合学部, 教授 (50380663) 白川敏夫九州産業大学, 建築都市工学部, 教授 (60623387)
Project Period (FY)	2021-04-01 – 2024-03-31
Keywords	副産粉体 / 有効利用 / コンクリート / 耐久性 / 外割混合
Outline of Final Research Achievements	In this study, the research team investigated the improved durability of concrete mixed with large quantity of by-product powders using the method proposed by the representatives through exposure experiments in real environments and accelerated tests in the laboratory, and also the relationship with the pore structure of the hardened concrete. As a result, it was confirmed that the concrete mixed large quantity of by-products has a significant effect on the deterioration that can be suppressed by densification of the hardened concrete structure. It was also revealed that carbonation has a high correlation with the amount of voids in the 40-120 nm range. Furthermore, the usefulness of durability evaluation using the surface water absorption test method devised by the co-author was demonstrated. On the other hand, it was also confirmed that air entrainment is essential in terms of frost damage, as is the case with general concrete.
Free Research Field	建築材料学
Academic Significance and Societal Importance of the Research Achievements	石炭火力発電所で発生するフライアッシュやコンクリート用砕石を製造する際に生じる砕石粉などは，セメントとは異なり水と練り混ぜても硬化しないのでコンクリートに混合すると種々の性能低下の原因となる。このことがこれらの粉体の有効利用における障害となるが，本研究で検討した方法でコンクリートに混合することによりコンクリートの耐久性能を損なうことなく，むしろ向上させながら大量に有効利用可能であることを示した。